(Very) Hard AND nice puzzles
The following list contains portal puzzles that have been rated as nice or very nice and that are difficult. These puzzles are recommended for experts - and allow some time to solve.
| Description | solved | Rating | |
|---|---|---|---|
 | Full Quads by mormagli (on 7. October 2022, 16:52) | 12 |  98 % |
| Paradigm Shift (S-Cell Japanese Sums Cipher) by Agent (on 7. March 2023, 09:00) | 28 | 98 % |
| X-sum, but in Chaos by SparkNights (on 21. September 2023, 06:00) | 37 | 96 % |
| Firework for Entropy No. 50 by Mad-Tyas (on 19. December 2023, 18:19) | 45 | 95 % |
| Sauntering Supernova by Groktilian (on 20. December 2023, 19:55) | 14 | 90 % |
| Return of the killer tomatoes (Shikaku killer) by PrimeWeasel (on 7. January 2024, 17:32) | 32 | 93 % |
| Stolen Numerals XV*V by NurglesGift (on 9. August 2024, 20:17) | 61 | 90 % |
| Coatlicue by aqjhs (on 12. December 2024, 14:41) | 36 | 93 % |
| Tom and Jerry by SXH (on 3. December 2024, 06:57) | 16 | 93 % |
| Echo Chamber by etoler (on 24. February 2025, 16:25) | 30 | 93 % |
| Chaos Construction: Internal X-Sums by KNT (on 11. July 2022, 23:23) | 76 | 99 % |
| Archers and Kings by SudokuExplorer (on 30. March 2021, 01:00) | 74 | 97 % |
| Deconstruksum [Position Sums Deconstruction] by Christounet (on 26. February 2023, 13:39) | 49 | 100 % |
| Count me out ! [Deconstruction] by Christounet (on 14. April 2023, 01:18) | 46 | 99 % |
| Anti-Knight Weirdity 5 by Jeet Sampat (on 25. February 2023, 20:19) | 44 | 94 % |
| Sparkle by Myxo (on 21. April 2024, 13:00) | 39 | 94 % |
| Line of Sight Chaos Production (9x9) by RockyRoer (on 4. February 2022, 03:10) | 33 | 100 % |
| Cages Constriction (Slitherlink Chaos Construction Sudoku) by rockratzero (on 8. April 2023, 10:43) | 36 | 94 % |
| Emergence by Jay Dyer (on 27. May 2024, 00:01) | 97 | 97 % |
| Japanische Summen 2358 by Uhu (on 3. September 2017, 17:47) | 56 | 98 % |
